CFTR and cystic fibrosis: Since mice do not recapitulate all of the hallmarks of human CF, considerable efforts were made to create other animal models. CFTR−/− rats were recently created using DNA editing and the resulting animals show a reduced airway-surface liquid (ASL) height and submucosal gland hypoplasia [71]. CFTR−/− and CFTRΔF508/ΔF508 pigs as well as CFTR−/− ferrets were generated by adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer [72, 73].